Centerless grinding machine



Oct. 28, 1930. JfA. PHL-:LPS

CENTERLESS GRINDING MACHINE Filed Dec. 3. 1927 2 Sheets-Sheet 1 GR om..wm Q. Il

J. A. PHELPS Oct. 28, 1930.

. CIEN'LlEaRLEsS GRINDING MACHINE 2 Sheets-Sheet 2 Filed DeC. 3, 1927 umi@ i l mmf. N

n A NN Patented Oct. 28, 1930k l UNITED STATES JAMES A. PHELPS, FCLEVELAND, OHIO CENTERLSS GRINDING MAC-EINE application med December s,1927. serial No. 237,464.

As the name implies, a centerless grinding machine is one of that typewhich supports or carries the work ground thereby without availing ofthe center supporting 'method so commonly called for grinding machines.This method of positloning the work has many obvious `advantagesrelative to the speed and accuracy with which the machine functions.

The centerless grinding machine generally speaking comprises a grindin,Wheel that revolves with a comparatively igh peripheral speed and aregulating wheel mounted in spaced relationv with respect to thegrinding wheel and turnin with a relatively small circumferentialvelocity; The work is posi-` tioned intermediate these wheelsand due totheir dierences in peripheral speeds, .a grinding action takes place.

-It is common practice to employ a blade intermediate the wheelsaforesaid for the purpose of assisting in vthepositioning of the work.It will be apparent that work positioned in this manner will be held bysupporting points which are non-equidistantly spaced thereabout; thatis, the distance between the first and second supporting points Y is 90as is the distance between the second and third, while that between thethird and 3o first is 180. Needless to say this condition does not addto the trueness and ineness of the finished work turned out by themachine. In addition there is the disadvantage of having a comparativelystationary support employed in conjunction with two so-called movablesupporting points.

I propose by this invention to obviate the above noted disadvantages byproviding a centerless grinding machine in which the work outinterfering with the operating is supported by three equidistantlyspacedv being a space provided between them and the grindin wheel and itis in this space that the wor is positioned. By this method the `work issupported at points substantially 120 apart. f

Centerless grindin machines are usually employed to grind cy indricalwork by 'either one of two methods, either the straight through grindingmethod or .the in-feed grlnding method. The first method is used whenthe work is entirely cylindrical and lacking in any shoulders orprotruding parts, the in-feed method being availed of with that type ofwork having shoulders, such as shackle bolts, yoke pins, valve-tappe'ts.A machine made in accordance with this inven-y tion does not depart fromthis conventional practice but includes' novel construction whichfacilitatesthe operation of themachine when the in--feed method isemployed. This feature is obtained b providing certain instrumentalitiesfor a usting the carrier rolls to size of work and additionalinstrumentalilties which operate to move one of the carrier rolls forthe purpose of positioning the work when the machine is to be used inconnection with'the in-feed method.

A still further object of Vthis invention is to Y provide a centerlessgrinding; machine in which the grinding wheel may be adjusted to variousangles with respect to the Work Withmethods of the machine. T attainthis end y mounting the grinding wheel onta bracket having eye-boltswhich move in an arcuate T-groovein a support. This eliminates anypivotal construction which would normally interfere with the operationof the machine.

In the now known types of centerless grinding machines, adjustment tothe size of work is obtained by variations in the position oftheregulating wheel, as Well as the supporting blade. An advantage ofparamount importance obtained by my centerless grinding machine is thefeature of imrobility of the regulating wheel notwithstandingthe'factth'at the machine is adjustable to accommodate work of widelyvarying dimensions. While my machine includes structure that permits ofthe adjustment of theposition of the grind- Apositions of the carrierrollswhereb are held against the regulating wheel by'gravity action. Itmight be well to mention that one of the main differences ofconstruction between my machine and the conventional machine of thistype is that in the old form there is a lateral relationship between thegrinding and regulating wheels while my invention provides for avertical relationship between these parts. That is, the grinding wheelis superimposed over the regulating wheel and it is such a constructionas this that permits me to avail of gravity action for the positioningand adjustment of the carrier rolls to the size of the work.

Various other more detailed objects and advantages will in part becomeapparent and in part be hereinafter stated as the description of theinvention proceeds. For a complete understanding thereof, reference maybe had to the following description and accompanying drawings, in whichFigure 1 is a side view of a centerless grinding machine made inaccordance with this invention, parts being br'oken away to more clearlyillustrate detailed features of the construction.

Figure 2 is a horizontal cross section taken on the line 2--2 of Figure1, parts being broken away and shown in section.

Figure 3 is a detailed plan view 'of the bracket on which the grindingwheel is mounted.

Figure 4 is a vertical cross section taken on the line 4-4 of Figure 1,and

Figure 5 is a vertical cross-section illustrating more particularlytheconstruction of 'the adjusting instrumentalities.

Throughout the various figures of the drawings, corresponding parts aredesignated by like referencecharacters.

While the preferred form of the invention is herein set forth, it is tobe understood that I am 'not to be limited to the exact constructionillusrated and described because various modifications in these detailsmay be provided in putting the invention into practise within the scopeof the appended claims.

KA grinding machine made along the lines of this invention includes anyappropriate support or stand illustrated in the drawings somewhatdiagrammatically and designated by the reference character A. The standA is of what might be called elongated formation and is providedintermediate its ends with a large groove or cutaway portion B.

A regulating wheel C is fixedly mounted in the groove B. This is alsoshown diagrammatically in the drawings as the particular mounting ofthis wheel has no bearing on this invention.

Positioned over the top of the stand A at one end thereof is asupporting plate 1 having an arcuate T-groove The plate 1 is alsopreferably formed with a flange 3 co-aligned with the groove 2. A topplate 4 having a groove 5 complemental to the flange 3 and adapted toreceive the same is positioned above the plate 1. Plate 4 carries headedbolts 6 which extend into the T-groove 2 whereby the plates 1 and 4 areheld in position with their adjacent faces in contact. It will beapparent that this connection affords a movable relationship betweenthese parts so that the plate 4 may slide over the plate 1 and be guidedin its movement by the iiange 3 and groove 2. At one side of plate 4 isan upstanding bracket 7. This bracket is supported by the curved flangemember 8 which also projects upwardly from the plate 4. Fastened to thetops of the bracket 7 and the flange 8, in any suitable manner as bybolts, is a plate 9 having an opening therein. The plate 9 extendsbeyond the bracket 7 and the opening is in this extension. The bracket 7has grooves 10 in its outer face which cooperate with flanges 11 on acomplemental supporting member 12 for the purpose of governing therelative movement between the member 12 and the bracket 7. The member 12has a hollowed-out shoulder or bracket 13 and a threaded opening 14. Ascrew-threaded arm 16 extends intothe opening 14 and passes through theopening in the plate 9 and has a hand-wheel 15 at one end thereof. It isnotable that the end of the arm 16 carrying the wheel 15 is enlarged at17 to provide a shoulder which bears against the plate 9. The hand-wheel15 is operable to raise and lower the supporting member 12 for purposesto be hereinafter more fully set out. A grinding Wheel 18 of properabrasive material is pivotally mounted in the bracket 13. It will beapparent that a movement of the supporting member 12 will cause acorresponding movement of the grinding wheel 18. l

Going back to the support or stand A, it is noted that this stand hastop portions 19 and 2Q in which are grooves 21 of the particularformation clearly shown in Flgure 4. Movable base members 22 and 24having flanges 23 corresponding in shape to the grooves 21 are mountedon the top portions 19 and 20 so that the flanges 23 fit in the grooves21 whereby the members 22 and 24 are movablelongitudinally with respectto the stand A. The members 22 and 24 have upstanding ears 25 and 26throu h which extend pivot members 27 and 28. arried by the members 22and 24 are brackets 29 and 30 which are mounted on the pivots 27 and 28.

Referring more particularly to Figure 1, it is noted that the brackets29 and 30 extend beyond the top portions 2O and 19 and over theregulating wheel C where their ends terminate short of one another.Pivotally mounted in the ends of the brackets 29 and 30 are carrierrolls or wheels 31 and 32. The carriers 31 and 32 rest on the regulatingwheel C. Certain mechanism is provided for adjusting the positions ofthe members 22 and 24 while additional ,adjusting instrumentalities arewill cause longitudinal movement of the member 22 and a correspondingadjustment of the carrier 32. In connection with the base member 24 Iprovide two sets of operating instrumentalities for'the purpose ofadjusting the position of the carrier member 31 mounted thereon. Athreaded shank 37 extends into the opening 33 in the member 24 but is ina sliding engagement therein. The shank 37 extends from a hand-wheel oroperating member 38. A second operating member 39 having a hub portion40 is also carried by the shank 37 and is threaded thereon. A portion ofthe hub 40 is reduced and extends into the counterbore 34 as shown at41. The reduced portion of the hub 40 is provided with a circumferentialgroove 42. A pin 43 is threaded in an opening in the member 24 and hasan end entering the groove 42. This pin 43 is provided with a dog pointwhich functions to prevent relative rotation between the hub 40 andmember 24 when the pin 43 is screwed down tight. When this pin is loose,hub ,member 40 may be rotated with respect to the member 24. The shank37 extends through a divided clamp 44 which may be tightened by means ofa bolt and nut 45 to prevent rotation of the shank 37.

Rolls 46 may be suitably mounted on the plate 1 to receive the work asit comes from the grindingv wheel. The rolls 46 should preferably besubstantially co-alignedwith the carriers 31 and .32, although it istrue that an exact co-aligned relation between these parts is not alwaysnecessary 1n view of the adjustability of the carriers 31 and 32.

When the machine is used to grind work by the straight through methodthe grinding wheel 18 is positioned at an angle w1th respect to thework. It is this angular relationship that feeds the work straightthrough the machine, no other means for this purpose being necessary.Adjustment to 'the slze of the work is obtained by operating hand wheels36 and 38 to properlyv locatel the carriers 31 and 32.L These carriersare also adjusted to compensate for the wear of the grinding wheel whenaccurate work 1s desired.

When the work the in-eed method for the grinding thereof.

In-the operation of the machine to carry out this method the grindingwheel is held at right angles with respect to the work which is notfedstraight through, in the manner described in the preceding paragraph,but is inserted from the side in conjunction with a proper 'manipulationof the carrier 31. As in the straight through method the hand wheels 36and 38 are employed to adjust the carriers to the size of the work andto compensate or wear, but the intermittent move- `ments of the carrier31 to allow for the insertionand removal of the work, are caused by theoperation of the member 39.

When the hand-wheel 38 is to be operated to adjust the position of themember 24, the bolt and nut 45 must be loose while the pin 43.isscreweddown tight so that relative r0- tationbetween the hub 40 and member 24is avoided. Upon turning the wheel 38, the shank 37 will be rotated tocause the desired shifting of the base member 24. When it is desired toemploy the operating member 39 for the purpose of adjusting the carrierroll 31, the nut and bolt 45 are tightened to rigidly clamp `the shank37 in thel clamp 44 and the pin 43 is loosened but ,one end thereofmaintained in engagement with the groove 42. The operating member 39 isnow free to rotate while the shank 37 is rigid. The relative movement ofthese parts. will cause the required movement of the member 24 aspreviously set out. i

If it is desired to operate the machine with the grinding wheel at anangle with respect to the work, this may be done by shifting the topplate 4 over the supporting .plate 1.

.The groove 2 and bolts 6 provide for the kthe vertical diameter of thegrinding wheel 18. It will be apparent that by varying the angle of thewheel with respect to the work, variety in the speed with which the workis fed through the machine is aii'orded. The plates 1 and 4 provide fora wide range of angular adjustment of the. grinding wheel in the mannerhereinbefore set out. While it is intended that the carriers 31 and 32may be adjusted to accommodate work, the dimensions 'of which varywithin reasonable range, the machine is capable of accommodating work ofwidely varied dimensions on account of the adjustability of the grindingwheel 18. However, the main reason for incorporating the Jfeature of adjustability into has any protrudingpart's" such as shoulders, it isnecessary to avail of` the mounting of the grinding Wheel is tocompensate for the Wear of the same. These Wheels may be used until theyhave beenl Worn down to a very small size when they are adjustablymounted in the manner described.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent of the United States is:

1. In a oenterless grinding machine of the class described, thecombination of a grinding wheel, a stationary regulating Wheel, andmeans for positioning work intermediate the grinding and regulatingWheels, said last named means being adjustable to accommodate Work ofvarying sizes.

2. In a centerless grinding machine of the class described, thecombination of a stationary grinding Wheel, a regulating Wheel, andmeans intermediate the Wheels for positioning Work so that the grindingand regulating Wheels 'are diametrically oppositely disposed withrespect to the Work whereby the latter is adapted to be operated on bythe grinding wheel, said last named means being adjustable toaccomlnodate Work of varying sizes.

3. A oenterless grinding machine of the class described comprising, incombination, a grinding Wheel, a regulating Wheel said grinding andregulating wheels being in effect stationary, and instrumentalitiesintermediate said Wheels for positioning Work to be op= erated onthereby,4 said instrumentalities being adjustable to accommodate Work ofvarying dimensions.

4. A oenterless grinding machine of the class described comprising, incombination, a grinding Wheel, means for holding the Work in position tobe operated on by the grinding Wheel, instrumentalities for adjustingthe last-named means to accommodate Work of varying dimensions, andadditional mechanism associated with the last-named instrumentalitiesoperable'to vary the position of a portion of the first-named means.

5. Grinding mechanism of the class described comprising, in combination,a grinding Wheela regulating wheel, and carrier members in engagementwith the regulating Wheel and spaced from the grinding wheel.

6. Grinding mechanism of the class described comprising, in combination,a grinding wheel, a regulating wheel, complemental carrier rolls inengagement with the regulat ing Wheel and spaced from the grinding wheeland each other, and means for adjusting the position of the carrierrolls.

7. Grinding mechanism of the class described comprising, in combination,a grinding Wheel, a regulating wheel,carrier rolls in engagement withthe regulating wheel, the carrier rolls being pivotally mounted inbrackets, and instrumentalities for moving said brackets whereby thecarrier rolls are adjustable to accommodatethe varying sizes of Work.

8. A oenterless grinding machine of the l class described, comprising,in combination, a stand, a regulating wheel mounted on said stand, agrinding Wheel superimposed overl said regulating Wheel, andinstrumentalities in engagement with said regulating Wheel for holdingWork in position to be operated on by the grinding Wheel, saidinstrumentalities being adjustable by mechanism operable to let themfall under gravity action or be moved upward against this force.

9. A oenterless grinding machine of the class described comprising, incombination, a regulating Wheel mounted on said stand, movable basemembers carried by the stand, carrier rolls connected to said movablebase members and in engagement With the regulating Wheel, a grindingWheel, instrumentalities for adjusting the position of said base membersand additional instrumentalities for adjustingthe position of one of thebase members whereby the machine is adapted ior grinding by theso-calledin-feed method.

10. Mechanism for positioning Work in a grinding machine comprising, incombination, carrier members, brackets on said carrier members, saidbrackets being pivotally mounted on said base members, the base membersbeing movable with respect to one another Whereby adjustment of theposition of the carrier members adapts the machine to work ofafaryingdimensions.

In testimony whereof I afi-ix my signature.

JAMES A. PHELPS.

